Insertion, deletion robust audio watermarking: a set theoretic, dynamic programming approach

Desynchronization vulnerabilities have limited audio watermarking's success in applications such as digital rights management (DRM). Our work extends (blind-detection) spread spectrum (SS) watermarking to withstand time scale desynchronization (insertion/deletions) by applying dynamic programming (DP). Detection uses short SS watermark blocks with a novel O(N log N) correlation algorithm that provides robustness to time shifts and the resulting offsets to the watermarking domain transform. To withstand insertion/deletion, DP techniques then search for sequences of blocks instead of detecting SS watermarks individually. This allows DP techniques to govern the tradeoff between long/short SS blocks for non-desynchronization/desynchronization robustness. However, high dimensional searches and short SS blocks both increase false detection rates. Consequently, we verify detections between multiple, simultaneously embedded watermarks. Embedding multiple watermarks while considering host interference, compression robustness, and perceptual degradation to the host audio is a complex problem, solved using a set theoretic embedding framework. Proposed techniques improve performance by multiple orders of magnitude compared with naive SS schemes. Results also demonstrate the tradeoff between non-desynchronization/desynchronization robustness.